The name "Chicago" is derived from a French rendering of the Native American word shikaakwa, known to botanists as Allium tricoccum, from the Miami-Illinois language. The first known reference to the site of the current city of Chicago as "Checagou" was by Robert de LaSalle around 1679 in a memoir.[14]Henri Joutel, in his journal of 1688, noted that the wild garlic, called "chicagoua", grew abundantly in the area.[15] According to his diary of late September 1687:

when we arrived at the said place called Chicagou which, according to what we were able to learn of it, has taken this name because of the quantity of garlic which grows in the forests in this region.[15]

In the mid-18th century, the area was inhabited by a Native American tribe known as the Potawatomi, who had taken the place of the Miami and Sauk and Fox peoples.[16] The first known non-indigenous permanent settler in Chicago was Jean Baptiste Point du Sable. Du Sable was of African and French descent and arrived in the 1780s.[17][18][19] He is commonly known as the "Founder of Chicago".

On August 12, 1833, the Town of Chicago was organized with a population of about 200.[23] Within seven years it grew to more than 4,000 people. On June 15, 1835, the first public land sales began with Edmund Dick Taylor as U.S. receiver of public moneys. The City of Chicago was incorporated on Saturday, March 4, 1837 and for several decades was the world's fastest growing city.[24]

A flourishing economy brought residents from rural communities and immigrants from abroad. Manufacturing and retail and finance sectors became dominant, influencing the American economy.[30] The Chicago Board of Trade (established 1848) listed the first ever standardized 'exchange traded' forward contracts, which were called futures contracts.[31]

To accommodate rapid population growth and demand for better sanitation, the city improved its infrastructure. In February 1856, Chicago's Common Council approved Chesbrough's plan to build the United States' first comprehensive sewerage system.[34] The project raised much of central Chicago to a new grade. While elevating Chicago, and at first improving the city's health, the untreated sewage and industrial waste now flowed into the Chicago River, then into Lake Michigan, polluting the city's primary freshwater source.

In 1871, the Great Chicago Fire destroyed an area of about 4 miles long and 1 mile wide, a large section of the city at the time.[38][39][40] Much of the city, including railroads and stockyards, survived intact,[41] and from the ruins of the previous wooden structures arose more modern constructions of steel and stone. These set a precedent for worldwide construction.[42][43] During its rebuilding period, Chicago constructed the world's first skyscraper in 1885, using steel-skeleton construction.[44][45]

The city grew significantly in size and population by incorporating many neighboring townships between 1851 and 1920, with the largest annexation happening in 1889, with five townships joining the city, including the Hyde Park Township, which now comprises most of the South Side of Chicago and the far southeast of Chicago, and the Jefferson Township, which now makes up most of Chicago's Northwest Side.[46] The desire to join the city was driven by municipal services the city could provide its residents.

Chicago's flourishing economy attracted huge numbers of new immigrants from Europe and migrants from the Eastern United States. Of the total population in 1900, more than 77% were either foreign-born or born in the United States of foreign parentage. Germans, Irish, Poles, Swedes and Czechs made up nearly two-thirds of the foreign-born population (by 1900, whites were 98.1% of the city's population).[47][48]

During the 1870s and 1880s, Chicago attained national stature as the leader in the movement to improve public health. City, and later state laws, that upgraded standards for the medical profession and fought urban epidemics of cholera, smallpox, and yellow fever were both passed and enforced. These laws became templates for public health reform in other cities and states.[51]

The city established many large, well-landscaped municipal parks, which also included public sanitation facilities. The chief advocate for improving public health in Chicago was Dr. John H. Rauch, M.D.. Rauch established a plan for Chicago's park system in 1866. He created Lincoln Park by closing a cemetery filled with shallow graves, and in 1867, in response to an outbreak of cholera he helped establish a new Chicago Board of Health. Ten years later, he became the secretary and then the president of the first Illinois State Board of Health, which carried out most of its activities in Chicago.[52]

In the 19th century, Chicago became the nation's railroad center, and by 1910 over 20 railroads operated passenger service out of six different downtown terminals.[53][54] In 1883, Chicago's railway managers needed a general time convention, so they developed the standardized system of North American time zones.[55] This system for telling time spread throughout the continent.

The ratification of the 18th amendment to the Constitution in 1919 made the production and sale (including exportation) of alcoholic beverages illegal in the United States. This ushered in the beginning of what is known as the Gangster Era, a time that roughly spans from 1919 until 1933 when Prohibition was repealed. The 1920s saw gangsters, including Al Capone, Dion O'Banion, Bugs Moran and Tony Accardo battle law enforcement and each other on the streets of Chicago during the Prohibition era.[63] Chicago was the location of the infamous St. Valentine's Day Massacre in 1929, where Al Capone sent men to gun down members of his rival gang, North Side, led by Bugs Moran.[64]

In 1924, Chicago was the first American city to have a homosexual-rights organization, the Society for Human Rights. This organization produced the first American publication for homosexuals, Friendship and Freedom. Police and political pressure caused the organization to disband.[65]

In March 1937, there was a violent strike by about 3,500 drivers for Checker and Yellow Cab Companies which included rioting that went on for weeks. The cab companies hired "strike breakers", and the cab drivers union hired "sluggers" who ragged through the downtown Chicago area looking for cabs and drivers not participating in the strike.[68]

Mayor Richard J. Daley, a Democrat, was elected in 1955, in the era of machine politics. Starting in the early 1960s due to blockbusting, many white residents, as in most American cities, left the city for the suburban areas. Whole neighborhoods were completely changed based on race.[70] Structural changes in industry, such as globalization and job outsourcing, caused heavy losses of jobs for lower skilled workers. In 1966, Martin Luther King, Jr. and Albert Raby led the Chicago Freedom Movement, which culminated in agreements between Mayor Richard J. Daley and the movement leaders.[71]

In 1983, Harold Washington became the first black mayor of the city of Chicago. Washington's first term in office directed attention to poor and previously neglected minority neighborhoods. He was re‑elected in 1987 but died of a heart attack soon after.[75] Washington was succeeded by 6th ward AldermanEugene Sawyer who was elected by the Chicago City Council and served until a special election.

Richard M. Daley, son of Richard J. Daley, was elected in 1989. His accomplishments included improvements to parks and creating incentives for sustainable development. After successfully standing for re-election five times, and becoming Chicago's longest serving mayor, Richard M. Daley declined to run for a seventh term.[76][77]

On February 23, 2011, former Illinois Congressman and White House Chief of Staff, Rahm Emanuel, won the mayoral election, beating five rivals with 55 percent of the vote,[78] and was sworn in as Mayor on May 16, 2011.

When Chicago was founded in 1833, most of the early building was around the mouth of the Chicago River, as can be seen on a map of the city's original 58 blocks.[82] The overall grade of the city's central, built-up areas, is relatively consistent with the natural flatness of its overall natural geography, generally exhibiting only slight differentiation otherwise. The average land elevation is 579 ft (176.5 m) above sea level. The lowest points are along the lake shore at 578 ft (176.2 m), while the highest point, at 672 ft (205 m), is the morainal ridge of Blue Island in the city's far south side.[83]

Major sections of the city include the central business district, called The Loop, and the North, the South, and West Sides.[88] The three sides of the city are represented on the Flag of Chicago by three horizontal white stripes.[89] The North Side is the most densely populated residential section of the city, and many high-rises are located on this side of the city along the lakefront.[90] The South Side is the largest section of the city, encompassing roughly 60% of the city's land area. The South Side contains the University of Chicago and most of the facilities of the Port of Chicago.[91]

In the late 1920s, sociologists at the University of Chicago subdivided the city into 77 distinct community areas, which can further be subdivided into over 200 informally defined neighborhoods.[92][93]

Chicago's streets were laid out in a street grid that grew from the city's original townsite plat, which was bounded by Lake Michigan on the east, North Avenue on the north, Wood Street on the west, and 22nd Street on the south.[94] Streets following the Public Land Survey System section lines later became arterial streets in outlying sections. As new additions to the city were platted, city ordinance required them to be laid out with eight streets to the mile in one direction and sixteen in the other direction (about one street per 201 meters by two in the other direction). The grid's regularity provided an efficient means of developing new real estate property. A scattering of diagonal streets, many of them originally Native American trails, also cross the city (Elston, Milwaukee, Ogden, Lincoln, etc.). Many additional diagonal streets were recommended in the Plan of Chicago, but only the extension of Ogden Avenue was ever constructed.[95]

In 2016, Chicago was ranked the sixth-most walkable large city in the United States.[96] Many of the city's residential streets have a wide patch of grass and/or trees between the street and the sidewalk itself. This helps to keep pedestrians on the sidewalk further away from the street traffic. Chicago's Western Avenue is the longest continuous urban street in the world.[97] Other famous streets include Michigan Avenue, State Street, Clark Street, and Belmont Avenue. The City Beautiful movement inspired Chicago's boulevards and parkways.

The destruction caused by the Great Chicago Fire led to the largest building boom in the history of the nation. In 1885, the first steel-framed high-rise building, the Home Insurance Building, rose in the city as Chicago ushered in the skyscraper era,[45] which would then be followed by many other cities around the world.[98] Today, Chicago's skyline is among the world's tallest and most dense.[99]

The city lies within the humid continental climate zone (Köppen: Dfa), and experiences four distinct seasons. Summers are warm to hot and often humid, with a July daily average of 75.8 °F (24.3 °C). In a normal summer, temperatures can exceed 90 °F (32 °C) as many as 21 days. Winters are cold and snowy with few sunny days, and the normal January high is just below freezing. Spring and autumn are mild seasons with low humidity. Dewpoint temperatures in the summer range from 55.7 °F (13.2 °C) in June to 61.7 °F (16.5 °C) in July.[111] The city is part of the USDA Plant Hardiness zone 6a, transitioning to 5b in the suburbs.[112]

According to the National Weather Service, Chicago's highest official temperature reading of 105 °F (41 °C) was recorded on July 24, 1934,[113] although Midway Airport reached 109 °F (43 °C) one day prior and recorded a heat index of 125 °F (52 °C) during the 1995 heatwave.[114] The lowest official temperature of −27 °F (−33 °C) was recorded on January 20, 1985, at O'Hare Airport.[111][114] The city can experience extreme winter cold waves and summer heat waves that may last for several consecutive days. Thunderstorms are common during the spring and summer months which may sometimes produce hail, high winds, and tornadoes.[115] Like other major cities, Chicago also experiences urban heat island, making the city and its suburbs milder than surrounding rural areas, especially at night and in winter. Also, the proximity to Lake Michigan keeps lakefront Chicago cooler in early summer and milder in winter than areas to the west.[116]

During its first hundred years, Chicago was one of the fastest-growing cities in the world. When founded in 1833, fewer than 200 people had settled on what was then the American frontier. By the time of its first census, seven years later, the population had reached over 4,000. In the forty years from 1850 to 1890, the city's population grew from slightly under 30,000 to over 1 million. At the end of the 19th century, Chicago was the fifth-largest city in the world,[124] and the largest of the cities that did not exist at the dawn of the century. Within sixty years of the Great Chicago Fire of 1871, the population went from about 300,000 to over 3 million,[125] and reached its highest ever recorded population of 3.6 million for the 1950 census.

In the 1920s and 1930s, the great majority of African Americans moving to Chicago were clustered in a so‑called "Black Belt" on the city's South Side.[126] By 1930, two-thirds of Chicago's African-American population lived in sections of the city which were 90% black in racial composition.[126] Chicago's South Side emerged as America's second-largest urban black concentration, following New York's Harlem.[126]

Since 2010, Chicago's population has rebounded adding nearly 25,000 people in the most recent 2015 population estimates.[127]

As of the 2010 census,[131] there were 2,695,598 people with 1,045,560 households living in Chicago. More than half the population of the state of Illinois lives in the Chicago metropolitan area. Chicago is one of the United States' most densely populated major cities, and the largest city in the Great Lakes Megalopolis. The racial composition of the city was:

The city's previous largest ethnic group, non-Hispanic white, declined from 59% in 1970 to 31.7% in 2010.[129]

Chicago has the third-largest LGBT population in the United States. In 2015, roughly 4% of the population identified as LGBT.[133][134] Since the legalization of same-sex marriage in the State of Illinois in 2013, nearly 10,000 same-sex couples have wed in Cook County, a majority in Chicago.[135]

According to the U.S. Census Bureau's American Community Survey data estimates for 2008–2012, the median income for a household in the city was $47,408, and the median income for a family was $54,188. Male full-time workers had a median income of $47,074 versus $42,063 for females. About 18.3% of families and 22.1% of the population lived below the poverty line.[136]

According to the 2008–2012 American Community Survey, the ancestral groups having 10,000 or more persons in Chicago were:[137]

Irish: (137,799)

Polish: (134,032)

German: (120,328)

Italian: (77,967)

American: (37,118)

English: (36,145)

African American: (32,727)

Russian: (19,771)

Arab: (17,598)

European: (15,753)

Swedish: (15,151)

Greek: (15,129)

French (except Basque): (11,410)

Ukrainian: (11,104)

West Indian (except Hispanic groups): (10,349)

Persons identifying themselves as "Other groups" were classified at 1.72 million, and unclassified or not reported were approximately 153,000.[137]

Chicago has the third-largest gross metropolitan product in the United States—about $630.3 billion according to 2014–2016 estimates.[9] The city has also been rated as having the most balanced economy in the United States, due to its high level of diversification.[143] In 2007, Chicago was named the fourth-most important business center in the world in the MasterCard Worldwide Centers of Commerce Index.[144] Additionally, the Chicago metropolitan area recorded the greatest number of new or expanded corporate facilities in the United States for calendar year 2014.[145] The Chicago metropolitan area has the third-largest science and engineering work force of any metropolitan area in the nation.[146] In 2009 Chicago placed 9th on the UBS list of the world's richest cities.[147] Chicago was the base of commercial operations for industrialists John Crerar, John Whitfield Bunn, Richard Teller Crane, Marshall Field, John Farwell, Julius Rosenwald and many other commercial visionaries who laid the foundation for Midwestern and global industry.

Manufacturing, printing, publishing and food processing also play major roles in the city's economy. Several medical products and services companies are headquartered in the Chicago area, including Baxter International, Boeing, Abbott Laboratories, and the Healthcare Financial Services division of General Electric. In addition to Boeing, which located its headquarters in Chicago in 2001, and United Airlines in 2011, GE Transportation moved its offices to the city in 2013, as did ThyssenKrupp North America, and agriculture giant Archer Daniels Midland.[6] Moreover, the construction of the Illinois and Michigan Canal, which helped move goods from the Great Lakes south on the Mississippi River, and of the railroads in the 19th century made the city a major transportation center in the United States. In the 1840s, Chicago became a major grain port, and in the 1850s and 1860s Chicago's pork and beef industry expanded. As the major meat companies grew in Chicago many, such as Armour and Company, created global enterprises. Though the meatpacking industry currently plays a lesser role in the city's economy, Chicago continues to be a major transportation and distribution center. Lured by a combination of large business customers, federal research dollars, and a large hiring pool fed by the area's universities, Chicago is also the site of a growing number of web startup companies like CareerBuilder, Orbitz, 37signals, Groupon, Feedburner, and NowSecure.[156]

Chicago is a major world convention destination. The city's main convention center is McCormick Place. With its four interconnected buildings, it is the largest convention center in the nation and third-largest in the world.[159] Chicago also ranks third in the U.S. (behind Las Vegas and Orlando) in number of conventions hosted annually.[160]

Chicago's minimum wage for non-tipped employees is one of the highest in the nation and will incrementally reach $13 per hour by 2019.[161]

Lakeview is home to Boystown (pronounced boys town), which, along with Andersonville, are some of the best-known LGBT neighborhoods in the nation. Each year in June, Boystown hosts the Chicago Pride Parade, one of the world's largest with over 1,000,000 people in attendance.

Chicago also has a nationally televised Thanksgiving parade that occurs annually. The McDonald's Thanksgiving Parade is seen across the nation on WGN-TV and WGN America, featuring a variety of diverse acts from the community, marching bands from across the country, and is the only parade in the city to feature inflatable balloons every year.[170]

Navy Pier, located just east of Streeterville, is 3,000 ft (910 m) long and houses retail stores, restaurants, museums, exhibition halls and auditoriums. In the summer of 2016, Navy Pier will have constructed their new DW60 Ferris wheel. Dutch Wheels a world renowned company that manufactures ferris wheels was selected to design the new wheel.[173] It will feature 42 navy blue gondolas that can hold up to eight adults and two kids. It will also have entertainment systems inside the gondolas as well as a climate controlled environment. The DW60 will stand at approximately 196 ft (60 m), which is 46 ft taller than the previous wheel. The new DW60 will be the first in the United States and will be the sixth tallest in the U.S.[174] Chicago was the first city in the world to ever erect a ferris wheel.

The Willis Tower (formerly named Sears Tower) is a popular destination for tourists. The Willis Tower has an observation deck open to tourists year round with high up views overlooking Chicago and Lake Michigan. The observation deck includes an enclosed glass balcony that extends 10 feet out on the side of the building. Tourists are able to look straight down.

In 2013, Chicago was chosen as one of the "Top Ten Cities in the United States" to visit for its restaurants, skyscrapers, museums, and waterfront, by the readers of Condé Nast Traveler.[176][177]

Chicago lays claim to a large number of regional specialties that reflect the city's ethnic and working-class roots. Included among these are its nationally renowned deep-dish pizza; this style is said to have originated at Pizzeria Uno.[178] The Chicago-style thin crust is also popular in the city.[179]

There are several distinctly Chicago sandwiches, among them the Italian beef sandwich, which is thinly sliced beef simmered in au jus and served on an Italian roll with sweet peppers or spicy giardiniera. A popular modification is the Combo—an Italian beef sandwich with the addition of an Italian sausage. Another is the Maxwell Street Polish, a grilled or deep-fried kielbasa — on a hot dog roll, topped with grilled onions, yellow mustard, and hot sport peppers.[184]

Ethnically originated creations include chicken Vesuvio, with roasted bone-in chicken cooked in oil and garlic next to garlicky oven-roasted potato wedges and a sprinkling of green peas. Another is the Puerto Rican-influenced jibarito, a sandwich made with flattened, fried green plantains instead of bread. There is also the mother-in-law, a tamale topped with chili and served on a hot dog bun.[185] The tradition of serving the Greek dish, saganaki while aflame, has its origins in Chicago's Greek community.[186] The appetizer, which consists of a square of fried cheese, is doused with Metaxa and flambéed table-side.[187]

Carl Sandburg's most famous description of the city is as "Hog Butcher for the World/Tool Maker, Stacker of Wheat/ Player with Railroads and the Nation's Freight Handler,/ Stormy, Husky, Brawling, City of the Big Shoulders."

Chicago literature finds its roots in the city's tradition of lucid, direct journalism, lending to a strong tradition of social realism. In the Encyclopedia of Chicago, Northwestern University Professor Bill Savage describes Chicago fiction as prose which tries to "capture the essence of the city, its spaces and its people". The challenge for early writers was that Chicago was a frontier outpost that transformed into a global metropolis in the span of two generations. Narrative fiction of that time, much of it in the style of "high-flown romance" and "genteel realism", needed a new approach to describe the urban social, political, and economic conditions of Chicago.[189] Nonetheless, Chicagoans worked hard to create a literary tradition that would stand the test of time,[190] and create a "city of feeling" out of concrete, steel, vast lake, and open prairie.[191] Much notable Chicago fiction focuses on the city itself, with social criticism keeping exultation in check.

Sporting News named Chicago the "Best Sports City" in the United States in 1993, 2006, and 2010.[194] Along with Boston, Chicago is the only city to continuously host major professional sports since 1871, having only taken 1872 and 1873 off due to the Great Chicago Fire. Additionally, Chicago is one of the six cities in the United States to have won championships in the four major professional leagues and, along with New York and Los Angeles, is one of three cities to have won soccer championships as well. Several major franchises have won championships within recent years – the Bears (1985), the Bulls (91, '92, '93, '96, '97, and '98), the White Sox (2005), the Cubs (2016), the Blackhawks (2010, 2013, 2015), and the Fire (1998).

The city has two Major League Baseball (MLB) teams: the Chicago Cubs of the National League play in Wrigley Field on the North Side; and the Chicago White Sox of the American League play in Guaranteed Rate Field on the South Side. Chicago is the only city that has had more than one MLB franchise every year since the AL began in 1901 (New York hosted only one between 1958 and early 1962). The Cubs are the oldest Major League Baseball team to have never changed their city;[citation needed] they have played in Chicago since 1871, and continuously so since 1874 due to the Great Chicago Fire. They have played more games and have more wins than any other team in Major League baseball since 1876.[195] They have won three World Series titles, but had the dubious honor of having the two longest droughts in American professional sports: They had not won their sport's title since 1908, and had not participated in a World Series since 1945, both records, until they beat the Cleveland Indians in the 2016 World Series.

The White Sox have played on the South Side continuously since 1901, with all three of their home fields throughout the years being within blocks of one another. They have won three World Series titles (1906, 1917, 2005) and six American League pennants, including the first in 1901. The Sox are fifth in the American League in all-time wins, and sixth in pennants.

With berths for more than 6,000 boats, the Chicago Park District operates the nation's largest municipal harbor system.[209] In addition to ongoing beautification and renewal projects for the existing parks, a number of new parks have been added in recent years, such as the Ping Tom Memorial Park in Chinatown, DuSable Park on the Near North Side, and most notably, Millennium Park, which is in the northwestern corner of one of Chicago's oldest parks, Grant Park in the Chicago Loop.

The government of the City of Chicago is divided into executive and legislative branches. The Mayor of Chicago is the chief executive, elected by general election for a term of four years, with no term limits. The current mayor is Rahm Emanuel. The mayor appoints commissioners and other officials who oversee the various departments. As well as the mayor, Chicago's clerk and treasurer are also elected citywide. The City Council is the legislative branch and is made up of 50 aldermen, one elected from each ward in the city.[212] The council takes official action through the passage of ordinances and resolutions and approves the city budget.[213]

During much of the last half of the 19th century, Chicago's politics were dominated by a growing Democratic Party organization. During the 1880s and 1890s, Chicago had a powerful radical tradition with large and highly organized socialist, anarchist and labor organizations.[214] For much of the 20th century, Chicago has been among the largest and most reliable Democratic strongholds in the United States; with Chicago's Democratic vote the state of Illinois has been "solid blue" in presidential elections since 1992. Even before then, it was not unheard of for Republican presidential candidates to win handily in downstate Illinois, only to lose statewide due to large Democratic margins in Chicago. The citizens of Chicago have not elected a Republican mayor since 1927, when William Thompson was voted into office. The strength of the party in the city is partly a consequence of Illinois state politics, where the Republicans have come to represent rural and farm concerns while the Democrats support urban issues such as Chicago's public school funding. Chicago contains less than 25% of the state's population, but 8 of Illinois' 19 U.S. Representatives have part of Chicago in their districts.

Machine politics persisted in Chicago after the decline of similar machines in other large U.S. cities.[215] During much of that time, the city administration found opposition mainly from a liberal "independent" faction of the Democratic Party. The independents finally gained control of city government in 1983 with the election of Harold Washington (in office 1983–1987). From 1989 until May 16, 2011, Chicago was under the leadership of its longest serving mayor, Richard M. Daley, the son of Richard J. Daley. On May 16, 2011, Rahm Emanuel was sworn in as the 55th mayor of Chicago. Because of the dominance of the Democratic Party in Chicago, the Democratic primary vote held in the spring is generally more significant than the general elections in November for U.S. House and Illinois State seats. The aldermanic, mayoral, and other city offices are filled through nonpartisan elections with runoffs as needed.

Formerly a state legislator representing Chicago and later a US Senator, the city is home of United States President Barack Obama and First Lady Michelle Obama. The Obama's residence is located near the University of Chicago in Kenwood on the city's south side.[216]

Chicago had a murder rate of 18.5 per 100,000 residents in 2012, ranking 16th among cities with 100,000 people or more.[217] This was higher than in New York City and Los Angeles, the two largest cities in the United States, which have lower murder rates and lower total homicides. However, it was less than in many smaller American cities, including New Orleans, Newark, and Detroit, which had 53 murders per 100,000 residents in 2012. The 2015 year-end crime statistics showed there were 468 murders in Chicago in 2015 compared with 416 the year before, a 12.5% increase, as well as 2,900 shootings—13% more than the year prior, and up 29% since 2013. Chicago had more homicides than any other city in 2015, according to the Chicago Tribune.[218]

According to reports in 2013, "most of Chicago's violent crime comes from gangs trying to maintain control of drug-selling territories",[219] and is specifically related to the activities of the Sinaloa Cartel, which by 2006 had decided to seek to control illicit drug distribution, against local street gangs.[220] Violent crime rates vary significantly by area of the city, with more economically developed areas having low rates, but other sections have much higher rates of crime.[219] In 2013, the violent crime rate was 910 per 100,000 people;[221] the murder rate was 10.4 – while high crime districts saw 38.9, low crime districts saw 2.5 murders per 100,000.[222]

The number of murders in Chicago peaked at 970 in 1974, when the city's population was over 3 million people (a murder rate of about 29 per 100,000), and it reached 943 murders in 1992, (a murder rate of 34 per 100,000).[223] However, Chicago and other major U.S. cities, experienced a significant reduction in violent crime rates through the 1990s, falling to 448 homicides in 2004, its lowest total since 1965 and only 15.65 murders per 100,000). Chicago's homicide tally remained low during 2005 (449), 2006 (452), and 2007 (435) but rose to 510 in 2008, breaking 500 for the first time since 2003.[224][225] In 2009, the murder count fell to 458 (10% down).[226] and in 2010 Chicago's murder rate fell to 435 (16.14 per 100,000), a 5% decrease from 2009 and lowest levels since 1965.[227] In 2011, Chicago's murders fell another 1.2% to 431 (a rate of 15.94 per 100,000).[228] but shot up to 506 in 2012.[229][230]

In 2012, Chicago ranked 21st in the United States in numbers of homicides per person, but in the first half of 2013 there was a significant drop per-person, in all categories of violent crime, including homicide (down 26%).[231] Chicago ended 2013 with 415 murders, the lowest number of murders since 1965, and overall crime rates dropped by 16 percent.[232] (In 1965, there were 397 murders.[233])

Jens Ludwig, director of the University of Chicago Crime Lab, estimated that shootings cost the city of Chicago $2.5 billion in 2012.[234]

In 2014, the Chicago police department reported a total murder count of 390 through December 20, 2014, according to the Chicago Sun-Times. That means that Chicago was able to record their lowest number of murder totals in close to five years for the second continuous calendar year, despite an overall increase in shootings. The Cook County medical examiner's office had reported a total of 410 homicides with 16 of those including fatal police shootings, all within the same time period.

Chicago high school rankings are determined by the average test scores on state achievement tests.[240] The district, with an enrollment exceeding 400,545 students (2013–2014 20th Day Enrollment), is the third-largest in the U.S.[241] On September 10, 2012, teachers for the Chicago Teachers Union went on strike for the first time since 1987 over pay, resources and other issues.[242] According to data complied in 2014, Chicago's "choice system", where students who test or apply and may attend one of a number of public high schools (there are about 130), sorts students of different achievement levels into different schools (high performing, middle performing, and low performing schools).[243]

Chicago is a major transportation hub in the United States. It is an important component in global distribution, as it is the third-largest inter-modal port in the world after Hong Kong and Singapore.[252]

Seven mainline and four auxiliary interstate highways (55, 57, 65 (only in Indiana), 80 (also in Indiana), 88, 90 (also in Indiana), 94 (also in Indiana), 190, 290, 294, and 355) run through Chicago and its suburbs. Segments that link to the city center are named after influential politicians, with three of them named after former U.S. Presidents (Eisenhower, Kennedy, and Reagan) and one named after two-time Democratic candidate Adlai Stevenson.

The Kennedy and Dan Ryan Expressways are the busiest state maintained routes in the entire state of Illinois.[253]

The Chicago Transit Authority (CTA) handles public transportation in the City of Chicago and a few adjacent suburbs outside of the Chicago city limits. The CTA operates an extensive network of buses and a rapid transit elevated and subway system known as the 'L' (for "elevated"), with lines designated by colors. These rapid transit lines also serve both Midway and O'Hare Airports. The CTA's rail lines consist of the Red, Blue, Green, Orange, Brown, Purple, Pink, and Yellow lines. Both the Red and Blue lines offer 24‑hour service which makes Chicago one of a handful of cities around the world (and one of two in the United States, the other being New York City) to offer rail service 24 hours a day, every day of the year, within the city's limits.

Metra, the nation's second-most used passenger regional rail network, operates an 11-line commuter rail service in Chicago and throughout the Chicago suburbs. The Metra Electric Line shares its trackage with Northern Indiana Commuter Transportation District's South Shore Line, which provides commuter service between South Bend and Chicago.

Pace provides bus and paratransit service in over 200 surrounding suburbs with some extensions into the city as well. A 2005 study found that one quarter of commuters used public transit.[254]

Chicago is the largest hub in the railroad industry.[258] Six of the seven Class I railroads meet in Chicago, with the exception being the Kansas City Southern Railway.[259] As of 2002, severe freight train congestion caused trains to take as long to get through the Chicago region as it took to get there from the West Coast of the country (about 2 days).[260] According to U.S. Department of Transportation, the volume of imported and exported goods transported via rail to, from, or through Chicago is forecast to increase nearly 150 percent between 2010 and 2040.[261] CREATE, the Chicago Region Environmental and Transport Efficiency program, comprises about 70 programs, including crossovers, overpasses and underpasses, that intend to significantly improve the speed of freight movements in the Chicago area.[262]

The Port of Chicago consists of several major port facilities within the city of Chicago operated by the Illinois International Port District (formerly known as the Chicago Regional Port District). The central element of the Port District, Calumet Harbor, is maintained by the U.S. Army Corps of Engineers.[266]

Iroquois Landing Lakefront Terminal: at the mouth of the Calumet River, it includes 100 acres (0.40 km2) of warehouses and facilities on Lake Michigan with over 780,000 square meters (8,390,000 square feet) of storage.

Lake Calumet terminal: located at the union of the Grand Calumet River and Little Calumet River 6 miles (9.7 km) inland from Lake Michigan. Includes three transit sheds totaling over 29,000 square meters (315,000 square feet) adjacent to over 900 linear meters (3,000 linear feet) of ship and barge berthing.

Electricity for most of northern Illinois is provided by Commonwealth Edison, also known as ComEd. Their service territory borders Iroquois County to the south, the Wisconsin border to the north, the Iowa border to the west and the Indiana border to the east. In northern Illinois, ComEd (a division of Exelon) operates the greatest number of nuclear generating plants in any US state. Because of this, ComEd reports indicate that Chicago receives about 75% of its electricity from nuclear power. Recently, the city began installing wind turbines on government buildings to promote renewable energy.[267][268][269]

Natural gas is provided by Peoples Gas, a subsidiary of Integrys Energy Group, which is headquartered in Chicago.

Domestic and industrial waste was once incinerated but it is now landfilled, mainly in the Calumet area. From 1995 to 2008, the city had a blue bag program to divert recyclable refuse from landfills.[270] Because of low participation in the blue bag programs, the city began a pilot program for blue bin recycling like other cities. This proved successful and blue bins were rolled out across the city.[271]

To celebrate the sister cities, Chicago hosts a yearly festival in Daley Plaza, which features cultural acts and food tastings from the other cities.[276] In addition, the Chicago Sister Cities program hosts a number of delegation and formal exchanges.[276] In some cases, these exchanges have led to further informal collaborations, such as the academic relationship between the Buehler Center on Aging, Health & Society at the Feinberg School of Medicine of Northwestern University and the Institute of Gerontology of Ukraine (originally of the Soviet Union), that was originally established as part of the Chicago-Kiev sister cities program.[278]

^ abMean monthly maxima and minima (i.e. the expected highest and lowest temperature readings at any point during the year or given month) calculated based on data at said location from 1981 to 2010.

^Official records for Chicago were kept at various locations in downtown from January 1871 to 31 December 1925, University of Chicago from 1 January 1926 to 30 June 1942, Midway Airport from 1 July 1942 to 16 January 1980, and at O'Hare Airport since 17 January 1980.[119][120]

^ ab"Timeline: Early Chicago History". Chicago: City of the Century. WGBH Educational Foundation And Window to the World Communications, Inc. 2003. Archived from the original on May 26, 2009. Retrieved May 26, 2009.